My favorite (and current go-to) program uses 80% of AirDNA figures for new STR properties without a rental history, but your current rents will provide a much more solid figure for underwriting. 

up from 1989, down from the all time high in 2005, and up from a recent low in 2016. 

Particularly in a college town there are a lot of opportunistic property investors and low quality property managers. 

We currently have StayFi on 27 homes and we hired a marketing company that does monthly email newsletter campaigns.

Currently,  I use direct mailers, so I am curious to know what avenues other take.

Your rental returns will be low compared to your purchase price. 

He lost his job and his mother is currently paying for the rent.

I currently own a duplex and I'm working on getting it out of my name and into the LLC's name.

I'd suggest looking for one with low-no fees as you're getting started out.

So, I generally work with what's there and try to add low hanging fruit amenities where possible.